Sealing assemblies for wheel-hub units for applications involving vehicle wheels are already known from the prior art and some examples are described in the documents U.S. Pat. No. 8,303,190 and US2012/0177315 In most cases, the sealing assemblies of the known type comprise a first and second annular screen mounted on the outer ring and inner ring, respectively, opposite each other so as to define between them an annular chamber inside which a series of sealing lips are arranged, the sealing lips being mounted on a fixed annular seal integral with one of the screens, generally the screen intended to remain stationary during use. Access to this chamber by the external contaminants (water, mud, dust) is limited by a particular form of one or both the screens which also cooperate, in a very close arrangement, with radially outer portions of the outer or inner ring of the bearing and/or of wheel-hub elements integral therewith, forming labyrinth seals.
Usually, the increase in the sealing performance of the sealing assemblies described above is obtained by means of an increase in the geometrical complexity of the screens and/or an increase in the number of sealing lips, but the constantly increasing demand for a reduction in fuel consumption and exhaust gas emissions, as well as the cost targets which must be met by the motor vehicle industry, have resulted in this complexity and increase being unprofitable in market terms.